Extract reading of input i/o to input

And add the ability of other modules to listen to either
the final result (a `Key`) or tap into the input as it is read

src/mpv/control.gleam

@@ -3,7 +3,7 @@ import gleam/result
 import gleam/string
 
 import input/key.{type Key}
-import mpv/internal/control as internal_control
+import mpv/internal as internal_control
 import tcp/reason.{type Reason}
 import tcp/tcp.{type Socket}